Radio receiving apparatus



Dec. 23, 1941. w. L. L. VlVlE RADIO RECEIVING APPARATUS Filed Dec. 15, 1938 INVENTOR W/LHEL/WZ/J' L. L. l lV/f ATTORNEY Patented Dec. 23, 1941 RADIO RECEIVING APPARATUS Wilhelmus Lambertus Leonardus Vivie, Eindhoven, Netherlands, assignor, by mesne assignments, to Radio Corporation of America, New York, N. Y., a corporation ofv Delaware Application December 15, 1938, Serial'No. 245,872

In the Netherlands December 24', 1937 3 Claims.

Radio receiving apparatus having automatic tuning efiected by means of one or more operating members such as press buttons are already known. In these apparatus use is made of a condenser of the rotatable electrode type 5 tuning to a station, by the position of a stop 3 which is controlledby the press buttons either which is coupled with the operating member of with the intermediary of a transmission mechathe station and which cooperates with a member nism or not. Due to the shape of the condenser secured to the shaft of the condenser, automatic plates it is practically impossible to construct tuning being thus brought about completely m these apparatus in such manner that with the chanically. The S ps y b j ble in such aid of such a press button system the apparatus manner that owing to the adjustment of the is automatically tuned over a large wave length stops a determined operating member may be range, for example, of from 200 to 600 ms. or utilized for each station desired. from 800 to 2000 ms. In one known form of In one advantageous embodiment the movable construction it is true that, therefore, the apshaft of the condenser has rigidly mounted n paratus is equipped with a comparatively large it a plate shaped member with which may conumber of press buttons but the wave length operate a plurality of operating members proranges which can be switched on with the aid vided with stops and arranged so as to bep of these buttons are all located within a comallel to the center line of this shaft. According paratively small region. It will be evident that to the invention, it is advisable that the operat an apparatus comprising such a press button ing members should be arranged, preferably in system finds little application in practice since One or more concentric ircles, u d th center the wave length range covered by it is too small. line of the movable shaft of the condenser, the owing to the fact that, in accordance with Whole of the tuning mechanism becoming thus the invention, the tuning condenser 'is of the greatly simplified. The construction may, of slidable-electrode type the conditions become course, be such that, when the apparatus is tuned quite difierent. A very slight relative displaceto a determined station and consequently a'dement in axial direction of the movable and th termined operating member such as a button is fixed condenser halves results in a great variam press d u p ss o another station and tion in capacity of the apparatus. According to s qu ly up p ss n in a t utt the ti by sing a condenser of the slidthe first button automatically returns to its posiable electrode type it is possible to utilize autot o of rest- If desired, there ay a so be p omatic tuning which covers, if desired, the whole ded, however, a particular member which reof the wave length range of t apparatus withstores a pressed in button to its position of rest. out any difficulty, so that if the means required In a further embodiment of the apparatus actheref r are present in t m a cording to the invention a plurality of stations crating member such as a press button may be are operated with the aid of a single operating provided for each station desired. The dimen- -member which is provided with a plurality of sions of the tuning condenser, which is formed 40 stops and which occupies a difierent position in as a slidable electrode condenser, remain in this the position of each 'of the stops. The presscase within quite permissible limits, which is not ing rod of the operating button may be provided, the case if use is made of a condenser of the for example, with recesses which are engaged by rotatable electrode type. Since with a slidable a pin. electrode condenser it is possible, in the case of In the apparatus according to the'invention permissible dimensions of the condenser, to take it is advisable'that the movable shaft of the cona very small ratio between the maximum and denser should always tend, in a manner known capacities, it is possible to construct per so by the action of a spring, t occupy its such a condenser so that without changing over, neutral position, said shaft being counteract d the whole of the wave length range, 1. e. from therein by the stop that has been pressed in. about 200-2000 ms., can be covered. Since there This stop, which is consequently coupled with is in this case no wave length switch, it is conthe operating member in question, is kept by an sequently possible to distribute the stations to arresting device in its pressed in position and be tuned by the operating members at will over thus as well as owing to the action of the spring the wave length ranges without being tied down the position of the shaft of the condenser is to one determined wave length range.

Automatic tuning may be effected in many ways. According to one advantageous embodiment the position of the slidable electrode condenser is determined, in the case of automatic The invention will be explained more fully with reference to the accompanying drawing in which Fig. 1 illustrates an embodiment of the invention wherein several tuning means are operated simultaneously; Fig. 2 illustrates a section through an embodiment of the invention incorporating radially spaced operating levers; Fig. 3 is an end view of the device shown in Fig. 2; Fig. 4 illustrates a detail of the arrangement shown in Fig. 2 pertaining to manual operation; and, Fig. 5 illustrates another form of the invention where a single push button may be used to adjust the tuning means to several positions.

Fig. 1 represents diagrammatically the automatic tuning mechanism present ina radio receiving apparatus, whereinthe operating members are formed by press buttons and the tuning condenser is of the slidable electrode type. This condenser is mounted in a casing 3 having arranged in its fixed condenser halves 'I and condenser portions 2 which are axially slidable with respect to the halves I. The slidable halves 2 are mounted on a continuous shaft 4 which passes through the front wall 6 of the condenser casing, a plate shaped member 5 being provided on a press buttons of which the buttons 9 and I are visible in the drawing. At their lower ends the buttons are provided with stops of which the stops II and I2 pertaining to the buttons 9 and II are shown in the figure. These stops cooperate with the plate 5. In Fig. 1 the button 9 is pressed in, with the result that, upon pressing in, the stop I I has come into contact with the plate 5. The stop and, therefore, also the condenser halves 2 over a certain distance to the right with the result that the tuning condenser has acquired acertain capacity which corresponds to the tuning to a determined station. Owing to the fact that the stops of the different press buttons have different lengths the plate and the shaft 4 are displaced,

upon pressing in the button 9, over a distance different from that upon pressing in the button III. From the figure it may, in fact, be seen that the stop l2 has a length different from that of the stop ll of the button 9. In Fig. 1 the mechanism by which a button once pressed in is kept in its pressed in position is omitted for the sake of simplicity. Use may be made, of course, of any desired number of buttons. It will be clear that by giving the plate 5 an appropriate shapethese buttons may also be arranged in any other- II has displaced this plate as well as the shaft 4 manner, for example, in the same manner in.

which the keys of a typewriter are arranged. If desired, the buttons may also be arranged in a plurality of concentric circles around,the axis X-X.

Figs. 2, 3 and 4 represent a system similar to that of Fig. 1, which shows the constructive details. It appears from Fig. 2 that the casing l3 containing the press buttons is secured by means of bolts I4 to a plate I5 which occupies a fixed position with respect to the front-plate 6 of the tuning condenser. In a casing 6 is arranged shaft 4 with movable condenser halves 2 and fixed also shown in Fig. 1. In the casing l2 a number of cylindrical bushes l8 are arranged concentrically around the axis X-X, said number corresponding to the number of press buttons with which the apparatus is equipped. It appears from Fig. 3 that there are twelve of them.

The press buttons have a sector shaped portion which is provided with a raised edge. The construction of the buttons 9 and It appears from Fig. 2; the segmental portion is formed by 941 and Illa respectively and the raised edge by lb and lllb respectively. In these buttons are rigidly mounted pressing rods 9 which have an internal screw thread 20 so that the stops II and I2 (the only stops which are shown) can be raised and lowered. This consequently afiords the possibility of adjusting each press button to any desired station. The pressing rods I! are provided with two conical parts 2| and 22 which form, with the aid of the groove located between these parts, the mechanism for retaining a button once pressed in until another button is being pressed in. For this purpose a plate 23 is arranged on the bottom of the casing l3 so as to be slightly rotatable about the axis X-X, said plate having holes 24 the number of which corresponds to the number of press buttons. These holes have a circular shape and a slightly conical cross section. Between the bottom of the casing 8 and this plate there are provided a few helical springs 25 by which the plate 23; is always adjusted with respect to the bottom in such manner that the holes in this plate only partially overlap the ends of the channels l8. When one of the press buttons is pressed in, the plate 23 owing to the conical shape of the part 2| and of the aperture 24 in question, is turned against the action of the springs 25 with respect to the bottom of the casing l3 to such an extent that the part 2| can pass through the holes in the casing and in the plate 23, which holes are in line with one another. whilst when the whole of the part 2| has passed through the aperture 24 the plate 23 slightly turns back owing to the action of the springs 25 and retains the pressed in button in the groove between the conical parts 2| and 22, the button being consequently maintained in its pressed in position. When now another button is pressed in, the plate 23 turns again with respect to the bottom of the casing l2 with the result that the button which is pressed in already and on which at the moment no pressure is exerted springs back under the action of the spring 26. If desired, one of the buttons l2 may be formed as a blind key without a stop so that when this button is pressed in the adjustment of the condenser is not altered but only the button that has been pressed in last springs back.

It may be desirable to provide the condenser not only with the above described press button system but also with the manual (consequently not automatic) adjustment which is usually employed in radio receivers. In this case there may 4 be provided on the bush 21 a gear wheel 28 which is in engagement with a pinion 29 mounted on' bush 2'! brings-about an axial displacement of the shaft 4. v

Fig. represents one embodiment of the apparatus wherein a single button allows of automatically tuning difierent stations. As in the preceding figures, I denotes the condenser casing, 4 denotes the shaft of the condenser and 5 designates the member mounted on the shaft and tending to move to the left under the action of the spring I. Numeral 3| denotes the pressing rod of a press button 32. This pressing rod is provided on one side with a projecting part 33 which is provided with a plurality of lugs 34 amounts depending upon the adjustment desired,thedisplaceable element being movable. to

any desired. position between two extreme positions, means for applying a substantially constant force to said displaceable element which tends to return the same to one of said extreme positions, a driving rodconnected tosaid displaceable element, a plurality of individually operable means positioned around said driving rod, each of said operable means acting through said driving rod and upon selective operation thereof to efiect the movement of said element to respectively difierent desired positions, and to which can each cooperate with a fixed pin 35.

Upon pressing in the button 32 one of these lugs comes into contact with the pin 35 which prevents the button 32 from springing back. In

some way or other thep in 35 may be brought out of engagement with the lugs 34 so that the button 32 is free to move again. By giving this button 32 different positions it is possible to choose any desired station.

I claim:

1. In radio receiving apparatus provided with an adjustable tuning means of the type wherein adjustments are made by longitudinal displacement, between two extreme positions, of one element of the tuning means within another element thereof different amounts depending upon the tuning adjustment desired, a driving rod connected to the adjustable element of the tune ing means, a plate mounted'on said driving roll, a plurality of selectively operable meanspositioned around the driving rod and cooperating with said plate so that upon operation of one of said selectively operable means the adjustable element of the tuning means is moved to a predetermined position.

2. In radio signalling apparatus provided with an adjustable tuning means of the type wherein adjustments are made by the longitudinal displacement of a movable element oithe tuning means within another element thereof different hold said displaceable element in the desired position, each of said means comprising a member adjustable with respect to said element whereby said different desired positions may be individually and adjustably predetermined.

3. 'In radio signalling apparatus provided with an adjustable tuning means of the type wherein tuning is accomplished by the displacement of one element of the tuning means within another element thereof, different amounts depending upon the wave length desired, a disc-like element divided into a plurality of selectively operable sectors representing respectively different predetermined positions of said displaceable ele-. ment within the other element of the tuning means, each of said selectively operable sectors acting upon individual operation thereof to effeet the movement of said displaceable element from any position of its adjustment to one of said respectively difierent predetermined positions and to hold the same in that position against the action of said returning force, and means acting upon operation of another one of said selectively operable sectors to release said displaceable element and to effect its movement to the position represented by said other one of said selectively operable means.

WILHELMUS LALIBERTUS LEONARDUS VIVIE. 

